Quantitative experimental evidence is presented for the progress zone theory of limb development. The theory, here formulated mathematically, states that the parts of the limb are specified in proximo-distal succession by an autonomous timing mechanism operating in a 'progress zone' of undifferentiated growing mesenchyme under the influence of the apical ectodermal ridge. By the exchange of dis...

As a part of a larger-scale research, the present study aimed to use the main tenets of sociocultural perspective; namely, mediation, internalization, zone of proximal development, and the activity theory, to analyze the novice and expert teachers’ professional development through personal practical theorizing as an awareness raising technique. Furthermore, the study attempted to identify the c...

This paper addresses the question of how teachers learn from experience during their pre-service course and early years of teaching. It outlines a theoretical framework that may help us better understand how teachers’ professional identities emerge in practice. The framework adapts Vygotsky’s Zone of Proximal Development, and Valsiner’s Zone of Free Movement and Zone of Promoted Action, to the ...

This article presents the outcomes of how Dynamic Assessment (DA) may be organized to function within a class’s Zone of Proximal Development (ZPD). The testing field also has recently undergone noticeable changes leading to a shift to use technology that is emerged in our era. The study investigated college students’ barriers and motivations for testing reading comprehension ability using the n...

introduction: despite extensive studies about effects of crataegus monogyna on cardiovascular diseases yet, a few study has been undertaken antiarrhythmic property of this plant. aims of the present study were: 1) to determine the protective role of methanolic extract of c.monogyna on the rate-dependent model and the concealed conduction . 2) to explore the role of na+-k+ a tpase in the protect...

tween Eurasia and Africa that result in a primary eastward-directed, low-velocity current flow along the mid-Cretaceous Eurasian, northern Tethys margin. This conclusion appears to be at odds with sedimentologic and paleontologic field evidence (2, 3) obtained from the Helvetic tectonic unit that is exposed in the northern Alps and represents the former northern Tethys margin in southern Europe...

AIMS Invaginations of the cellular membrane called t-tubules are essential for maintaining efficient excitation-contraction coupling in ventricular cardiomyocytes. Disruption of t-tubule structure during heart failure has been linked to dyssynchronous, slowed Ca(2+) release and reduced power of the heartbeat. The underlying mechanism is, however, unknown. We presently investigated whether eleva...

Objective Although proximal neck dilatation following infrarenal endovascular aneurysm repair (EVAR) is common and associated with graft failure, little known about sealing zone its clinical relevance fenestrated EVAR (FEVAR). We studied seal (PSD) dynamics FEVAR assessed significance.

The morphology of the transition zone between the terminal plate of the basal body and the 9 + 2 region of the somatic (non-oral) cilium has been examined in Paramecium tetraurelia. Freeze-fracture and thin-section techniques disclosed both membrane specializations and various internal structural linkages. Freeze-fracture material revealed sets of particles interrupting the unit membrane. The m...